As die-bonding materials for semiconductors, there are conventionally known Au—Si eutectic crystals, solders, resin paste compositions or the like. Among these materials, the resin paste compositions have been extensively used in view of high working efficiency and low costs.
In general, semiconductor devices have been manufactured by bonding elements such as semiconductor chips onto a lead frame through a die-bonding material. The semiconductor elements such as semiconductor chips have been required to have a high reliability of their properties such as electrical conductivity, thermal conductivity and bond strength with the enhancement of integration and fineness of the respective elements.
To meet the above requirements, it may be considered that resin paste compositions used for bonding the elements such as semiconductor chips onto the lead frame contain a conductive filler such as a metal powder, for example, a gold powder, a silver powder and a copper powder. Among these resin paste compositions, those containing a silver powder have been predominantly employed at the present time because the silver powder is not as rare as the gold powder and not readily oxidized nor deteriorated in storage stability as compared to the copper powder, and further is excellent in not only working efficiency and mechanical properties but also various other properties required for the resin paste compositions (refer to Patent Document 1, etc.).
However, the silver powder itself is a noble metal material and therefore still a rare material. For this reason, there is an increasing demand for die-bonding materials using the other more available filler material. However, at present, there have not been obtained any resin paste compositions using an alternate material for the silver powder which are capable of exhibiting properties equal to or superior to those using the silver powder.